Osmotic systems manufactured in the form of osmotic devices for delivering a beneficial agent to an environment of use are known to the art in U.S. Pat. Nos. 3,845,770 and 3,916,899. The systems in these patents are made with a semipermeable wall that surrounds a compartment containing an agent. The wall is permeable to an external fluid, substantially impermeable to agent, and there is a passageway through the wall for dispensing agent from the system. These systems are extraordinarly effective for delivering an agent that is soluble in the fluid and exhibits an osmotic pressure gradient across the wall against the fluid, and also for delivering an agent that has limited solubility in the fluid and is admixed with an osmotically effective compound that is soluble in the fluid and exhibits an osmotic pressure gradient across the wall against the fluid. These systems release agent by fluid being continuously imbibed through the wall into the compartment at a rate determined by the permeability of the wall and the osmotic pressure gradient across the wall to produce a solution of soluble agent, or a solution of soluble compound containing agent which solution in either operation is dispensed from the system. While the above systems are outstanding and represent a pioneer advancement in the delivery art, and while they are useful for dispensing numerous beneficial agents to an environment of use, there is a rare instance where the environment or the agent may have an unwanted effect on the system that can lead to unwanted results. For example, when the system is placed in an environment that can harm the wall, or the system contains an agent that can harm the wall, in either instance by slowly dissolving or hydrolyzing the wall over a prolonged period of time, these actions can change the system's rate of imbibition that can concomitantly lead to an uncontrolled rate of agent release over a correspondingly prolonged period of time.